The present invention relates to the handling of cast iron pipes exiting from centrifuging machines and a coating station. More specifically, the invention relates to the handling of the pipes on a horizontal or approximately horizontal transporter between the manufacturing exit of such pipes and a transporter for producing beds of pipes arranged head to tail, in an even or odd number, a female bell joint of one pipe alternating with a smooth male end of the next pipe. The successive beds are intended to be superposed to produce bound bundles.
Since the bundles of pipes to be produced must have sizes and weights compatible with handling devices and vehicles, the invention relates particularly to pipes with small diameters of 60 to 300 mm or, if need be, medium diameters not exceeding 600 mm.
Whether the beds comprise an even number or an odd number of pipes, one joint alternates with a smooth end in the bundles produced, both horizontally on the same bed and vertically between two superposed adjacent beds. The result is that the preparation of the beds to be superposed consists of bringing the pipes onto a horizontal transporter, with all the joints being oriented in the same direction, and turning one pipe out of two by 180.degree. by means of a hoisting and turning device known as a turner, at a fixed turning station. Downstream from the turning station, the pipes are removed to produce successive beds and then are stacked on a packing and removal carriage and banded.
For the purpose of counting, with a view to producing beds to be stacked, the pipes are received individually on V-shaped supports spaced at regular intervals known as steps on the horizontal transporter. Endless chains of the transporter advance intermittently with regularly spaced stop times to enable the pipe depositing, turning and removal operations.
The known technique therefore enables one pipe out of two to be turned by 180.degree. during a stop by the transporter at a fixed turning station, provided that all the consecutive V-shaped supports carry a pipe, or if this requirement is not met, provided that the transporter advances step by step over any empty supports.
For reasons of quality control and productivity, however, neither of these two requirements are met. The pipes are manufactured in pairs in twin centrifuging machines and are deposited in pairs on two pairs of consecutive V-shaped supports of the transporter which, for this reason, advances two steps at a time. Moreover, upstream of the turner, quality control of the pipes is carried out and the unsatisfactory pipes are withdrawn from time to time, either to be touched up or rejected. The result is that, with an advance of two steps and with a transporter which is not completely stacked with pipes, there PG,4 is an increased probability that the turner finds either an empty pair of V-shaped supports or a pipe which is not to be turned (the pipe to be being either one step upstream or downstream of the turning station). In other words, there is a high probability that the turner finds it impossible to rotate one pipe out of two since the advance is two steps at a time.
The problem at the turning station is thus to take one pipe out of two in spite of a two step advance and empty supports, i.e. in spite of the pipe to be turned not always being presented at a distance or multiple of two steps from the turning station but, on the contrary, often at a distance of one or an odd number of steps from the station.